JPH0193028A - Manufacture of reinforcement type cathode-ray tube - Google Patents

Abstract

PURPOSE:To stabilize the reinforcement effect at the part of the side surface of a cathode-ray tube where the tensil stress is the largest by making a reinforcement band adhere closely to the largest outer diameter part of the side surface of the cathode-ray tube, and after that, filling an adhesive in a clearance generated between the side surface of the face side and the reinforcement band. CONSTITUTION:At first, a cloth tape 8 an adhesive is spread is wound near the largest outer diameter part 5 of the side surface of a panel 2 of a cathode- ray tube 1. Then, a reinforcement band 9 which consists of iron whose peripheral length is a little shorter than the largest outer diameter part 5 of the cathode-ray tube 1 is prepared. The band 9 is expanded by heating, fixed near the largest outer diameter part 5 of the cathode-ray tube 1, and cooled. As the band 9 is cooled, it adheres closely to the side surface of the cathode-ray tube 1 through the tape 8. In this case, a clearance is generated between the band 9 and the side surface of the cathode-ray tube 1. The cathode-ray tube 1 is fixed to position the face 6 horizontal, an adhesive 10 of a low viscosity epoxy type is filled in the clearance pouring from the face 6 side, and hardened ti attach the band 9 to the side surface of the cathode-ray tube 1 closely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a reinforced cathode ray tube, and more particularly to a method for manufacturing a cathode ray tube E having a flat face.

[Conventional technology]

A cathode ray tube is a hollow glass container that is evacuated to a vacuum, so if it breaks due to scratches or impact, it will implode and scatter glass fragments, creating a dragon horn. In order to prevent this implosion, methods such as placing a metal band on the side surface that does not interfere with the image receiving area and fixing it with adhesive, or reinforcing the band by shrinking it and crimping it are used. Relevant reinforcement methods of this type include, for example, Japanese Patent Publications No. 42-4934 and Japanese Patent Publication No. 34984-1984.

In recent years, the face has become flat and the mechanical strength of the blown tube has become weaker, so there has been an increased need to stabilize the reinforcing effect. Figure 3 shows an example of the stress exerted on the outer surface of a cathode ray tube with a flat face when it is subjected to vacuum.

The number indicates the magnitude of the stress; if it is positive, it is tensile stress, and if it is negative, it is compressive stress. -Glass is weak in tension, so areas with large positive numbers are more likely to break.

Note that 1 indicates a cathode ray tube, 2 indicates a panel, and 3 indicates a funnel.

As is clear from the figure, the cathode ray tube 1 has become evacuated.
is most likely to break, i.e., a positive number (tensile stress)
The location 4 where .

Therefore, it is preferable to provide a reinforcing band to this portion 4.

However, due to the manufacturing method, panel 2 is made by press V molding a dish-shaped panel, so the joint between the molds has the maximum outer diameter of panel 2, and both sides with that part 5 as the border are The diameter becomes smaller. Therefore, even if a reinforcing band is arranged, as the diameter becomes smaller, a gap tends to be formed between the reinforcing band and the side surface of the panel 2, and the gap becomes unstable.

[Problem that the invention seeks to solve]

In the case of Brown WG, which has a flat face, as mentioned above, a gap easily appears between the reinforcing band and the side of the panel, and the gap becomes unstable. Therefore, fiber is used as an adhesive between the reinforcing band and the panel. Of course, tape made of material impregnated with adhesive cannot close the gap. Also, with normal adhesive, depending on the size of the gap, if there is too little, it will not be possible to fill the gap, and if there is too much, the adhesive will overflow into the excess area and adhere to the image surface, impairing the performance of the cathode ray tube, or removing it. (This causes the inconvenience that it takes time and effort. In other words, in the conventional technology, there was a problem that the part that required the most reinforcement did not have a stable structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a reinforced cathode ray tube, which can stably obtain a reinforcing effect at the portion of the side surface of the cathode ray tube where the tensile stress is maximum.

[Means for solving problems]

The purpose of the above is to attach a reinforcing band in close contact with the maximum outer diameter portion of the side surface of the cathode ray tube, and then apply adhesive from the face side to the gap created between the reinforcing band and the side surface on the face side from the maximum outer diameter portion. This is achieved by filling the

[Effect]

When the reinforcing band is placed in close contact with the maximum outer diameter part of the side surface of the cathode ray tube, the gap between the side surface of the cathode ray tube and the reinforcing band that is formed on the face side of that part becomes stable, and the maximum part of the child stress exists in that gap. I will do it. Therefore, a fluid adhesive is injected from the face side, filled, and cured.Thus, it is possible to stably bond the reinforcing band to the side of the CRT, which is the part where the stress caused by evacuating the CRT is greatest. be able to. Furthermore, by bringing the reinforcing band into close contact with the maximum outer diameter portion of the side surface of the cathode ray tube, when the adhesive is filled from the face side, the adhesive will not flow below the maximum outer diameter portion.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The panel 2 of the cathode ray tube 1 has a dish-like shape and consists of a face 6 coated with a phosphor 7 that produces an image on the inner surface, and a side surface including a maximum outer diameter portion 5. In the present invention, it is preferable that the face 6 be flat or nearly stiff, so the face 6 in this embodiment is flat, and the cross section of the cathode ray tube 1 shown in FIG. 1 is approximately the same over the entire circumference.

First, the maximum outer diameter portion 5 of the side surface of the panel 2 of the cathode ray tube 1
A cloth tape 8 for applying adhesive is wrapped around the area. Next, prepare an annular reinforcing band 9 made of iron with a circumference slightly shorter than the maximum outer diameter part 5 of the cathode ray tube 1, and heat it to 400 to 500 degrees Celsius to expand it.
It is strained so that its circumferential length is longer than the maximum outer diameter portion 5 of the cathode ray tube 1, and is inserted into the vicinity of the maximum outer diameter portion 5 of the cathode ray tube 1 and cooled.

The reinforcing band 9 is in close contact with the side surface of the cathode ray tube 1 via the cloth tape 8 for cooling.

As shown in FIG. 1, near the maximum outer diameter portion 5 of the cathode ray tube 1, the reinforcing band 9 is in close contact with the side surface of the cathode ray tube 1, but as it moves away from the face 6 of the cathode ray tube, the side surface of the cathode ray tube 1 becomes inclined. As a result, a gap is created between the reinforcing band 9 and the side surface of the cathode ray tube 1. As explained in FIG. 3, the portion 4 where the tensile stress is maximum and requires reinforcement most is the portion near the face 6f on the side surface of the cathode ray tube 1. If there is a gap in this area and the reinforcing band 9 does not come into close contact with the side surface of the cathode ray tube 1, the reinforcing effect will be lost.

Therefore, the cathode ray tube 1 is fixed so that the face 6 of the cathode ray tube 1 is almost horizontal, and a low viscosity epoxy adhesive 10 is injected from the face 6 side to fill the gap.
When cured, the reinforcing band 9 and the side surface of the cathode ray tube 1 are bonded together. In this case, the maximum outer diameter fM55 of the cathode ray tube 1
Since the reinforcing band 9 is in close contact with the adhesive 10, the adhesive 10 does not flow below the maximum outer diameter portion 5.

〔Effect of the invention〕

According to the present invention, the reinforcing band and the side surface of the cathode ray tube can be stably bonded at the part where the tensile stress on the side surface of the cathode ray tube is maximum (i.e., the maximum outer diameter of the panel and the middle part of the face). Therefore, a stable reinforcing effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, FIG. 2 is an external perspective view of FIG. 1, and FIG. 3 is a sectional view showing an example of stress distribution occurring on the outer surface of a cathode ray tube. 1... Braun tube, 5... Maximum outer diameter part,
6...Face, 8...Cloth tape, 9...
... Reinforcement band, 10... Adhesive. Figure 1 5: Maximum 71 circumference - 10 2 buildings 1 completed 1 2nd E! 1 N CRT 6:) ;-S 9: N Y 7 y nt°゛Figure 3 Town

Claims (1)

[Claims] 1. In a method for manufacturing a reinforced cathode ray tube, in which a reinforcing band is attached to the side surface of the cathode ray tube, the reinforcing band is attached in close contact with the maximum outer diameter portion of the side surface of the cathode ray tube, and then the reinforcing band is attached to the side surface from the maximum outer diameter portion to the face side. 1. A method for manufacturing a reinforced cathode ray tube, characterized in that an adhesive is filled from the face side into the gap formed between the reinforcing band and the reinforcing band.